The Malaysian government has ordered police to randomly check mobile phones for pornographic images.
New technology is proving a challenge for Malaysian censorship
The move follows reports by a local newspaper that young people were swapping sex videos and images on their mobile phones.
Deputy Interior Minister, Noh Omar, said he worried the practice was becoming increasingly common.
Officers have been ordered to immediately delete any explicit images they find stored in the phones.
The owners of internet cafes are also being targeted and will face prosecution if they allow customers to download pornographic material.
Phone shop operators who provide download services for sex images could also be charged for its possession, according to the New Straits Times newspaper.
Possessing pornography in Malaysia carries a maximum punishment of five years in prison and 50,000 ringgit (US$13,292 or £7,374) in fines.
According to the Malay language newspaper, Harian Metro, teenagers are using their mobile phones to video mass sex parties and then send the pictures to each other.
The BBC's Jonathan Kent in Kuala Lumpur says new technology is challenging the government's strict censorship laws, among the most rigid in Asia.
Pornography is illegal in Malaysia, a country whose population is mainly Muslim and where state television censors images of people kissing.
But the popularity of the internet means the government has to balance its commitment not to censor the net with attempts to stem the spread of pornographic material.